i18n resource consolidation

The Aggregator will consolidate requests for i18n resources based on the available locales. If a request is made for a non-locale specific resource (e.g. dijit/nls/common), then the Aggregator will include in the response the locale specific versions of the resource for the locales specified in the request.

i18n resources are assumed to reside in a directory named nls, with default resources residing in the nls directory and locale specific resources located in directories under the nls directory where the directory names are the same as the locale names.

The locales to be included in the response, if available on the server, are specified using the locs query arg (e.g. &locs=en,es). For dojo, the dojo http transport extension sets the locs query arg based on the values of the dojo.locale and djConfig.extraLocales properties.